This invention relates to a method and apparatus for transferring objects generally in a rectalinear path through a given distance. For example, in the field of steel making it is well known to utilize reheat furnaces for the purpose of heating steel slabs to maintain the slabs at a hot working temperature during rolling operations. Such reheat furnaces often have been characterized as walking-beam furnaces as a reference to the structural arrangement by which the steel slabs are supported and moved through the furnace from the charge to the discharge end thereof.
Of course, it will be appreciated that the references herein to walking beam type reheat furnaces are exemplary in nature and that the invention is not limited to use in a walking beam furnace or in steel making generally, but may be applied in any of a wide variety of applications which require movement of an article or articles along a rectilinear path to achieve the ends of a given manufacturing process or operation. This being understood, the invention will be described specifically with reference to a walking-beam type reheat furnace for purposes of convenient description.
In conventional walking-beam reheat furnaces, the slabs or billets to be heated are spaced one from another and the furnace is provided with first and second support structures, one of which is stationary and the other which is moveable through a sequence of well known motions to produce, by repetition of the sequence of motions, a "walking" translational motion. More specifically, in a conventional walking beam type furnace, the walking beam assembly includes movable slab support beams with support surfaces which initially are located at an elevation below the elevation of the stationary slab support surfaces, and are therefore disengaged from the slabs. The slab support beams are moved vertically upward to engage the slabs and lift them from the stationary support surfaces, after which the walking beam assembly is actuated to move the slab supporting beams, and therefore the slabs themselves, laterally in rectalinear translational motion through a given distance. The walking beam assembly is then further actuated to lower the slabs once again onto the stationary support beams, and is then lowered further to disengage the walking beam support surfaces from the slabs so that the slabs are again supported entirely by the stationary support beams. The walking beams assembly may then be further actuated to retract the laterally moveable elements thereof to their initial position to repeat the above described cycle thereby achieving the well known "walking" translational motion.
Any of a variety of mechanical systems may be employed to impart the desired cycles of vertical and lateral motion to a walking beam structure, including but not limited to screw jacks or hydraulic jacks, cams or eccentric drives, inclined plane arrangements, rack and pinion arrangements, and others used individually or in combination to produce the desired motion. Any of these, and others, may be employed to produce the desired mechanical motion in the present invention as hereinbelow described.
Although prior walking beam arrangements such as above characterized have generally served their intended purpose, there remains in the art considerable motivation, due to pressures of competition, escalating energy costs and other inflationary pressures for example to develop improved walking beam systems and similar work piece translating apparatus.